U.S. patent number 11,079,551 [Application Number 16/717,559] was granted by the patent office on 2021-08-03 for liquid crystal on silicon element for dual-functionality beam steering in wavelength selective switches.
This patent grant is currently assigned to Lumentum Operations LLC. The grantee listed for this patent is Lumentum Operations LLC. Invention is credited to Paul Colbourne, Sheldon McLaughlin, Peter David Roorda.
United States Patent |
11,079,551 |
Roorda , et al. |
August 3, 2021 |
Liquid crystal on silicon element for dual-functionality beam
steering in wavelength selective switches
Abstract
An optical device may include a monolithic beam steering engine.
The device may include a twin M.times.N wavelength selective switch
(WSS) including a first M.times.N WSS and a second M.times.N WSS.
The first M.times.N WSS may include a first panel section of the
monolithic beam steering engine to perform first beam steering of
first beams, wherein the first beam steering is add/drop port beam
steering; and a second panel section of the monolithic beam
steering engine to perform second beam steering of second beams,
wherein the second beam steering is common port beam steering. The
first M.times.N WSS may include a first optical element aligned to
the monolithic beam steering engine to direct one of the first
beams or the second beams relative to the other of the first beams
or the second beams, such that the first beams are directed in a
different direction from the second beams.
Inventors: |
Roorda; Peter David (Ottawa,
CA), Colbourne; Paul (Ottawa, CA),
McLaughlin; Sheldon (Ottawa, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Lumentum Operations LLC |
San Jose |
CA |
US |
|
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Assignee: |
Lumentum Operations LLC (San
Jose, CA)
|
Family
ID: |
71122054 |
Appl.
No.: |
16/717,559 |
Filed: |
December 17, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200209485 A1 |
Jul 2, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62787558 |
Jan 2, 2019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B
6/3518 (20130101); G02B 26/0833 (20130101); H04J
14/0212 (20130101); H04J 14/0217 (20130101); G02B
6/3594 (20130101); G02B 6/3534 (20130101); G02B
6/3546 (20130101); G02B 6/29383 (20130101) |
Current International
Class: |
H04J
14/02 (20060101); G02B 6/35 (20060101); G02B
26/08 (20060101); G02B 6/293 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Yuan et al: "Fully Integrated N.times.N MEMS Wavelength Selective
Switch with 100% Colorless Add-Drop Ports",OFC/NFOEC 2008, paper
OWC2 (Year: 2008). cited by examiner .
Shifu Yuan et al., "Fully Integrated N.times.N MEMS Wavelength
Selective Switch with 100% Colorless Add-Drop Ports". 2007, 3
pages. cited by applicant .
Leonid Pascar et al., "Port-Reconfigurable, Wavelength-Selective
Switch Array for Colorless/Directionless/Contentionless Optical
Add/Drop Multiplexing", 2015, 3 pages. cited by applicant .
Nicolas K. Fontaine et al., "N.times.M Wavelength Selective
Crossconnect with Flexible Passbands", 2012, 3 pages. cited by
applicant.
|
Primary Examiner: Liu; Li
Attorney, Agent or Firm: Harrity & Harrity, LLP
Parent Case Text
RELATED APPLICATION(S)
This application claims priority to U.S. Provisional Patent
Application No. 62/787,558, filed on Jan. 2, 2019, and entitled
"M.times.N WAVELENGTH SELECTIVE SWITCH USING A SINGLE LIQUID
CRYSTAL ON SILICON PANEL," the content of which is incorporated by
reference herein in its entirety.
Claims
What is claimed is:
1. An optical device, comprising: a monolithic beam steering
engine; and a twin M.times.N wavelength selective switch (WSS)
including a first M.times.N WSS and a second M.times.N WSS, the
first M.times.N WSS comprising: a first panel section of the
monolithic beam steering engine to perform first beam steering of
first beams, wherein the first beam steering is add/drop port beam
steering, and wherein the first panel section has a first geometric
configuration; a second panel section of the monolithic beam
steering engine to perform second beam steering of second beams,
wherein the second beam steering is common port beam steering, and
wherein the second panel section has a second geometric
configuration different from the first geometric configuration; and
a first optical element aligned to the monolithic beam steering
engine to direct one of the first beams or the second beams
relative to the other of the first beams or the second beams, such
that the first beams are directed in a different direction from the
second beams, and the second M.times.N WSS comprising: a third
panel section of the monolithic beam steering engine to perform
third beam steering of third beams, wherein the third beam steering
is add/drop port beam steering, and wherein the third panel section
has the first geometric configuration; a fourth panel section of
the monolithic beam steering engine to perform fourth beam steering
of fourth beams, wherein the fourth beam steering is common port
beam steering, and wherein the fourth panel section has the second
geometric configuration; and a second optical element aligned to
the monolithic beam steering engine to direct one of the third
beams or the fourth beams relative to the other of the third beams
or the fourth beams, such that the third beams are directed in a
different direction from the fourth beams.
2. The optical device of claim 1, wherein the first beams are
non-dispersed spectrum beams and the second beams are dispersed
spectrum beams.
3. The optical device of claim 1, wherein the third beams are
non-dispersed spectrum beams and the fourth beams are dispersed
spectrum beams.
4. The optical device of claim 1, wherein the first optical element
and the second optical element are a same optical element.
5. An M.times.N wavelength selective switch (WSS), comprising: a
monolithic beam steering engine, comprising: a first panel section
to perform first beam steering of first beams, wherein the first
beam steering is add/drop port beam steering, and wherein the first
panel section has a first geometric configuration; a second panel
section to perform second beam steering of second beams, wherein
the second beam steering is common port beam steering, and wherein
the second panel section has a second geometric configuration
different from the first geometric configuration; a third panel
section to perform third beam steering of third beams, wherein the
third beam steering is add/drop port beam steering, and wherein the
third panel section has the first geometric configuration; and a
fourth panel section to perform fourth beam steering of fourth
beams, wherein the fourth beam steering is common port beam
steering, and wherein the fourth panel section has the second
geometric configuration; and at least one optical element aligned
to the beam steering engine to: direct one of the first beams or
the second beams relative to the other of the first beams or the
second beams, such that the first beams are directed in a different
direction from the second beams, and direct one of the third beams
or the fourth beams relative to the other of the third beams or the
fourth beams, such that the third beams are directed in a different
direction from the fourth beams.
6. The M.times.N WSS of claim 5, wherein the at least one optical
element is aligned to the first panel section to direct the first
beams in a first direction that is different from a second
direction of the second beams.
7. The M.times.N WSS of claim 5, wherein the at least one optical
element is aligned to the second panel section to direct the second
beams in a second direction that is different from a first
direction of the first beams.
8. The M.times.N WSS of claim 5, wherein the first panel section
includes areas for receiving the first beams that are larger
relative to areas on the second panel section for receiving the
second beams.
9. The M.times.N WSS of claim 5, wherein an optical path between
the monolithic beam steering engine and the at least one optical
element is direct.
10. The M.times.N WSS of claim 5, wherein the at least one optical
element is at least one of a mirror or a prism.
11. The M.times.N WSS of claim 5, wherein the monolithic beam
steering engine is a liquid crystal on silicon (LCOS) panel.
12. The M.times.N WSS of claim 5, further comprising: a set of add
ports aligned to the first panel section; and a set of drop ports
aligned to the first panel section.
13. The M.times.N WSS of claim 5, further comprising: a set of
common ports aligned to the second panel section.
14. The M.times.N WSS of claim 5, further comprising: an optical
path for a dispersed spectrum beam, comprising: a first path
section from a common port to the second panel section, a second
path section from the second panel section to one or more optical
components, a third path section from the one or more optical
components to the first panel section, and a fourth path section
from the first panel section to an add port or drop port.
15. The M.times.N WSS of claim 14, wherein the at least one optical
element is disposed in one of the second path section or the third
path section.
16. The M.times.N WSS of claim 5, wherein the M.times.N WSS is one
of: a twin M.times.N WSS, a triple M.times.N WSS, or a quad
M.times.N WSS.
17. A method of controlling an M.times.N wavelength selective
switch (WSS), comprising: configuring, by a device, a first panel
section of a monolithic beam steering engine to perform first beam
steering of first beams, wherein the first panel section has a
first geometric configuration; configuring, by the device, a second
panel section of the monolithic beam steering engine to perform
second beam steering of second beams, wherein the second panel
section has a second geometric configuration different from the
first geometric configuration, and wherein one of the first panel
section or the second panel section is aligned to at least one
optical element to separate a direction of the first beams from the
second beams; configuring, by the device, a third panel section of
the monolithic beam steering engine to perform third beam steering
of third beams, wherein the third panel section has the first
geometric configuration; and configuring, by the device, a fourth
panel section of the monolithic beam steering engine to perform
second beam steering of second beams, wherein the fourth panel
section has the second geometric configuration, and wherein one of
the third panel section or the fourth panel section is aligned to
the at least one optical element to separate a direction of the
third beams from the fourth beams.
18. The method of claim 17, wherein configuring the first panel
section comprises: configuring pixels of a liquid crystal on
silicon (LCOS) panel.
19. The method of claim 17, wherein configuring the second panel
section comprises: configuring pixels of a liquid crystal on
silicon (LCOS) panel.
20. The method of claim 17, wherein the monolithic beam steering
engine is configured to at least one of: have steering angles less
than a threshold angle, or perform beamforming for less than a
threshold quantity of ports.
Description
TECHNICAL FIELD
The present disclosure relates to an M.times.N wavelength selective
switch (WSS) and to an M.times.N WSS that includes a multi-function
liquid crystal on silicon (LCOS) panel to provide add/drop port
beam steering and common port beam steering.
BACKGROUND
An M.times.N WSS is a device capable of independently routing any
wavelength channel (e.g., a wavelength channel included in an
optical signal comprising one or more wavelength channels) from any
inbound port of the M.times.N WSS to any outbound port of the
M.times.N WSS. In some cases, an M.times.N WSS may, along with one
or more other devices, be included in an optical node (e.g., a node
in a dense wavelength division multiplexed (DWDM) optical
communications system) in order to support add/drop of optical
signals at the optical node. In such an optical node, use of the
M.times.N WSS may support add/drop such that a given wavelength
channel can be added to or dropped from any degree of the optical
node. The M.times.N WSS may include a set of beam steering optical
elements to direct beams between input ports, output ports, common
ports, and/or the like.
SUMMARY
According to some possible implementations, an optical device may
include a monolithic beam steering engine. The device may include a
twin M.times.N wavelength selective switch (WSS) including a first
M.times.N WSS and a second M.times.N WSS. The first M.times.N WSS
may include a first panel section of the monolithic beam steering
engine to perform first beam steering of first beams, wherein the
first beam steering is add/drop port beam steering; and a second
panel section of the monolithic beam steering engine to perform
second beam steering of second beams, wherein the second beam
steering is common port beam steering. The first M.times.N WSS may
include a first optical element aligned to the monolithic beam
steering engine to direct one of the first beams or the second
beams relative to the other of the first beams or the second beams,
such that the first beams are directed in a different direction
from the second beams.
According to some possible implementations, an M.times.N WSS may
include a monolithic beam steering engine. The monolithic beam
steering engine may include a first panel section to perform first
beam steering of first beams, wherein the first beam steering is
add/drop port beam steering; and a second panel section to perform
second beam steering of second beams, wherein the second beam
steering is common port beam steering. The M.times.N WSS may
include at least one optical element aligned to the beam steering
engine to direct one of the first beams or the second beams
relative to the other of the first beams or the second beams, such
that the first beams are directed in a different direction from the
second beams.
According to some possible implementations, a method of controlling
an M.times.N WSS may include configuring a first panel section of a
monolithic beam steering engine to perform first beam steering of
first beams; and configuring a second panel section of the
monolithic beam steering engine to perform second beam steering of
second beams, wherein one of the first panel section or the second
panel section is aligned to at least one optical element to
separate a direction of the first beams from the second beams.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of an optical node including a wavelength
selective switch (WSS).
FIG. 2 is a diagram of a wavelength selective switch (WSS) with a
microelectromechanical system (MEMS) array.
FIGS. 3A and 3B are diagrams of an M.times.N WSS with a liquid
crystal on silicon (LCOS) panel to perform add/drop port beam
steering and common port beam steering.
FIGS. 4A and 4B are diagrams of LCOS panels, in a twin M.times.N
WSS, to perform add/drop port beam steering and common port beam
steering.
FIG. 5 is a diagram of an LCOS panel, in a twin M.times.N WSS, with
a prism in an optical path of add/drop port beams or common port
beams.
FIG. 6 is a flowchart of an example process for configuring a beam
steering engine to perform add/drop port beam steering and common
port beam steering in a WSS.
DETAILED DESCRIPTION
The following detailed description of example implementations
refers to the accompanying drawings. The same reference numbers in
different drawings may identify the same or similar elements.
In an optical communications system, wavelength selective switches
(WSSs) may be deployed to provide add and drop functionality at
nodes of the optical communications system. The WSS may have beam
steering elements, such as microelectromechanical system (MEMS)
mirror arrays to provide beam steering. However, to satisfy a
demand for increasing data transmission capacity in optical
communications systems, a quantity of optical nodes and associated
WSSs that are deployed may be increased. Available space for
optical nodes and associated WSSs may remain fixed even as a
quantity of optical components that are deployed increases. Thus,
in order to increase capacity in an optical node, WSSs should be
capable of beam steering in reduced form factors. Moreover, to
enable rapid deployment of optical nodes to increase optical
communications system coverage, a cost associated with components
of a WSS should be decreased.
However, using a dedicated MEMS mirror array for beam steering with
a WSS may result in an increased form factor to position the
dedicated MEMS mirror array within an optical path of the WSS.
Moreover, MEMS mirror arrays may be expensive, which may provide a
limit on a rate at which new optical nodes can be deployed to
increase capacity within an optical communications system.
Furthermore, MEMS mirror arrays may be subject to issues with
durability as a result of mechanical failures in components of the
MEMS mirror arrays.
Some implementations described herein provide a design for an
M.times.N WSS that is capable of performing beam steering for an
optical communications system using a multi-function beam steering
engine. For example, rather than including both a liquid crystal on
silicon (LCOS) panel and a MEMS mirror array to perform beam
steering within the WSS, the WSS may use a single LCOS panel
configured into multiple panel sections to perform beam steering
for both common ports and add/drop ports. In this way, a quantity
of components within the WSS is decreased, thereby reducing cost,
size, complexity, failure rate, and/or the like. Moreover, by using
steering angles less than a threshold, an insertion loss penalty of
the LCOS panel is reduced to an acceptable amount for optical
communications system deployment. Moreover, by using single
direction beam steering (e.g., positive beam steering angles), an
LCOS panel may achieve acceptable isolation performance for optical
communications systems, as described in more detail herein.
FIG. 1 is a diagram of an example optical node 100 using a WSS
described herein. As shown in FIG. 1, optical node 100 includes a
set of degrees 102-1 through 102-X (X>1). As shown, each degree
102 includes a multiplexing/demultiplexing stage 104 (e.g., 104-1
through 104-X) and an optical channel monitor 106 (e.g., 106-1
through 106-X). As further shown, each multiplexing/demultiplexing
stage 104 includes a pair of WSSs 108 (e.g., WSS 108-1A and WSS
108-1B through WSS 108-XA and WSS 108-XB). As shown, a first WSS
108 of each pair (e.g., WSS 108-1A, WSS 108-XA) is coupled to an
input fiber (e.g., 150-1, 150-X) associated with a respective
degree 102, while a second WSS of each pair (e.g., WSS 108-1B, WSS
108-XB) is coupled to an output fiber (e.g., 155-1, 155-X)
associated with the respective degree 102.
As further shown, optical node 100 includes add/drop stage 120. As
shown, add/drop stage 120 includes a set of WSSs 122 (e.g., WSS
122-1 and WSS 122-2). WSS 122 is a hybrid add/drop device that
supports colorless-directionless-contentionless (CDC) (e.g., each
transmitter can be any wavelength, send signals in any direction to
any degree, and multiple copies of the same wavelength can be
routed independently from different transmitters to different
degrees) add/drop of optical signals at optical node 100. As shown
in FIG. 1, a first WSS 122 (e.g., WSS 122-1), associated with
dropping optical signals at optical node 100, may be coupled to a
set of optical receivers (RX) 124. While not shown, in some cases,
the first WSS 122 may be coupled to a set of splitters, where the
set of splitters is coupled to the set of optical receivers (RX)
124. Similarly, a second WSS 122 (e.g., WSS 122-2), associated with
adding optical signals at optical node 100, may be coupled to a set
of optical transmitters (TX) 126.
A degree 102 bi-directionally connects optical node 100 to another
optical node or an endpoint node of, for example, a DWDM optical
communications system. For example, WSS 108-1A may receive an input
signal from another optical node via an optical fiber. Here, if a
portion of the input signal (e.g., one or more wavelength channels)
is to be dropped, then WSS 108-1A may selectively provide the
portion of the input signal (e.g., an optical signal including the
one or more wavelength channels, sometimes referred to as a
wavelength channel sub-beam) on a drop path to one or more optical
receivers 124 (e.g., a path from WSS 108-1A, via WSS 122-1, to one
or more optical receivers 124). Further, if a portion of the input
signal is to continue on an outbound optical fiber of another
degree 102 (e.g., is not to be dropped), then WSS 108-1A may
selectively provide the portion of the input signal on an express
path to an outbound WSS 108 associated with the other degree 102
(e.g., a path from WSS 108-1A to WSS 108-XB).
As another example, WSS 108-1B may provide an output signal to
another optical node via an optical fiber. Here, WSS 108-1B may
receive an optical signal, added at optical node 100, on an add
path from optical transmitter 126 (e.g., a path from optical
transmitter 126, via WSS 122-2, to WSS 108-1B), and provide an
output signal, including the optical signal, via the optical fiber.
Similarly, WSS 108-1B may receive a portion of an input signal on
an express path from an inbound WSS 108 (e.g., WSS 108-XA)
associated with another degree 102, and may provide an output
signal, including the portion of the input signal, via the optical
fiber.
In optical node 100, any wavelength may be switched to any fiber
direction (any degree), and multiple channels of the same
wavelength can be concurrently routed between a
transmitter/receiver of optical node 100 and a target
outbound/inbound optical fiber of optical node 100. In other words,
optical node 100 is capable of achieving CDC add/drop.
The number and arrangement of devices shown and described in
association with FIG. 1 are provided as examples. In practice,
optical node 100 may include additional devices, fewer devices,
different devices, differently arranged devices, and/or differently
sized devices than those shown in FIG. 1.
FIG. 2 is a diagram of an example 200 described herein. Example 200
is an example of a WSS with two MEMS mirror arrays (e.g., MEMS
micromirror arrays).
As shown in FIG. 2, example implementation 200 includes an
M.times.N WSS 200, which includes an input fiber array 202 of M
input fibers, an input microlens array 204 of M microlenses, a
collimating lens 206, a focusing lens 207, a diffraction grating
208, a roof prism 210, a first MEMS micromirror array 212, a
switching lens 214, a second MEMS micromirror array 216, and an
output fiber array 218 of N output fibers. In some implementations,
add/drop ports associated with output fiber array 218 may connect
to a single common port. In contrast, common ports associated with
input fiber array 202 and an input fiber 201 may be connected to
multiple add/drop ports to independently direct different
wavelengths to the different add/drop ports.
In operation, input fiber 201 of input fiber array 202 emits a
diverging light beam 221, which is collimated by a corresponding
microlens of the microlens array 204 to form a spot 222.
Diffraction grating 208 spreads the beam 221 into a plurality of
wavelength channel sub-beams (e.g., each sub-beam carries a
separate wavelength channel). Diffraction grating 208 disperses the
plurality of the wavelength channel sub-beams, which are coupled by
the focusing lens 207, through roof prism 210, onto MEMS
micromirror array 212, such that each of the micromirrors thereof
is illuminated by a corresponding set of wavelength channel
sub-beams of a corresponding set of M input fibers. In some cases,
MEMS micromirror array 212 may be an LCOS panel. The beam angle of
each wavelength channel sub-beam reflected from a corresponding
MEMS micromirror is determined by a tilt of the corresponding MEMS
micromirror, which is configured based on a control signal applied
to each MEMS micromirror of MEMS micromirror array 212.
A reflected wavelength channel sub-beam 223 of beam 221 propagates
back through roof prism 210, focusing lens 207, diffraction grating
208, and lens 206. Lens 206 focuses wavelength channel sub-beam 223
into a spot 224 at an intermediate focal plane 226. Switching lens
214 acts as an angle-to-offset converter. Since the beam angles of
individual wavelength channel sub-beams are individually determined
by the angle of tilt of corresponding micromirrors of the MEMS
micromirror array 212, then the wavelength channel sub-beams
emitted by the input fiber 201 can be individually directed to fall
on a corresponding micromirror of the second MEMS micromirror array
216.
The second MEMS micromirror array 216 has N micromirrors
corresponding to N output fibers of output fiber array 218. Second
MEMS micromirror array 216 couples a wavelength channel sub-beam
falling onto a micromirror thereof to an output fiber corresponding
to the micromirror. In this way, any one of a set of K wavelength
channel sub-beams in the input fiber 201 is independently
switchable into any particular one of the N output fibers,
depending upon the individually controllable tilt angles of
corresponding MEMS micromirrors of the MEMS micromirror arrays 212
and 216. Similarly, wavelength channel sub-beams 225 emitted by an
input fiber 205 of the input fiber array 202 are independently
switchable. However, providing two MEMS micromirror arrays (e.g.,
MEMS micromirror arrays 212 and 216) or a MEMS micromirror array
(e.g., MEMS micromirror array 216) and an LCOS panel (e.g., rather
than MEMS micromirror array 212) may result in an excessively large
form factor, increased cost, reduced durability, and/or the like.
Thus, in some implementations described herein, a single LCOS panel
may replace both MEMS micromirror arrays shown in FIG. 2. Although
some implementations are described herein in terms of a particular
layout of optical components, as shown, other layouts are
possible.
As indicated above, FIG. 2 is provided merely as an example. Other
examples may differ from what is described with regard to FIG.
2.
FIGS. 3A and 3B are diagrams of an example implementation of an
M.times.N WSS 300 described herein.
As shown in FIG. 3A, M.times.N WSS 300 may include an input fiber
array 302 (e.g., which may correspond to input fiber array 202),
and output fiber array 304 (e.g., which may correspond to output
fiber array 218), a set of optical components 306 (e.g., which may
correspond to one or more of components 204, 206, 208, 210, 214,
and/or the like), and a steering engine 308. Steering engine 308
may be configured to form two LCOS panel sections 310-1 and 310-2.
For example, steering engine 308 may receive a control signal
(e.g., from a control device of M.times.N WSS 300 and may configure
two sets of pixels of steering engine 308 to form two independent
steering engines 308 from the single steering engine 308.
In some implementations, steering engine 308 may include a set of
path sections, such as a first path section between input fiber
array 302 and a first subset of optical components 306, a second
path section between the first subset of optical components 306 and
a first panel section 310-1, a third path section between first
panel section 310-1 and a second subset of optical components 306,
a fourth path section between the second subset of optical
components 306 and a second panel section 310-2, a fifth path
section between the second panel section 310-2 and a third subset
of optical components 306, and/or a sixth path section between the
third subset of optical components 306 and output fiber array 304.
Although optical components 306 are shown as being in an optical
path of each path section, some path sections may include no
optical components 306.
In some implementations, steering engine 308 may be a monolithic
steering engine. For example, steering engine 308 may be a single
structure that is dividable, using control signaling, into multiple
panel sections to perform multiple beam steering functionalities.
In this case, steering engine 308 may be divided into a first panel
section 310-1 to perform first beam steering of first beams (e.g.,
non-dispersed spectrum beams associated with add/drop ports of
M.times.N WSS 300) and a second panel section 310-2 to perform
second beam steering of second beams (e.g., dispersed spectrum
beams associated with common ports of M.times.N WSS 300).
In some implementations, steering engine 308 may be an LCOS panel.
For example, steering engine 308 may be an LCOS panel (e.g., an
LCOS phased array) with pixels of the LCOS panel configured to
perform beam steering functionalities, such as a first set of
pixels being configured to form first panel section 310-1 and a
second set of pixels being configured to form second panel section
310-2. In this case, first panel section 310-1 may correspond to
MEMS micromirror array 212 in FIG. 2 and perform beam steering for
non-dispersed spectrum beams associated with add/drop port ports of
M.times.N WSS 300 (e.g., which may be a first subset of ports of
input fiber array 302 and output fiber array 304). An optical path
of the set of optical components 306 is arranged such that rather
than directing dispersed beams toward another, separate beam
steering component (e.g., MEMS micromirror array 216), the optical
path may direct a dispersed beam toward panel section 310-2 for
dispersed beam steering associated with common ports of M.times.N
WSS 300 (e.g., which may be a second subset of ports of input fiber
array 302 and output fiber array 304). In this way, a single
steering engine 308 may replace multiple MEMS micromirror arrays or
replace a combination of an LCOS panel and a micromirror array,
thereby achieving reduced form factor, reduced cost, and improved
durability.
In some implementations, steering engine 308 may achieve less than
a threshold insertion loss. For example, steering engine 308 may
achieve an insertion loss of less than 9 decibels (dB) in
connection with beam steering. In this case, steering engine 308
may restrict steering angles to less than a threshold angle and/or
may perform beam steering for less than a threshold quantity of
ports to ensure performance of less than the threshold insertion
loss.
FIG. 3B shows a plan view of steering engine 308. For example,
panel section 310-1 may be configured with areas 312-1 through
312-K to perform non-dispersed beam steering for beams with a
concentrated beam profile, as shown. In contrast, panel section
310-2 may be configured with areas 314-1 through 314-L to perform
dispersed beam steering for beams with a dispersed spectrum, as
shown. Areas 314 may be larger than areas 312 to enable reception
of different wavelengths of light of the beams with a dispersed
spectrum. For example, each of areas 314-1 through 314-L may be a
region at which steering engine 308 receives of multiple spots
corresponding to multiple wavelengths of light of a corresponding
beam. In this case, for a single 4.times.16 WSS, steering engine
308 may include a set of 17 areas 312 for beam add/drop port beam
steering (1 of which may be blocked using a reflector 316) and a
set of 4 areas 314 for common port beam steering.
As indicated above, FIGS. 3A and 3B are provided merely as one or
more examples. Other examples may differ from what is described
with regard to FIGS. 3A and 3B.
FIGS. 4A and 4B are diagrams of example of a steering engines
400/400' described herein. As shown in FIGS. 4A and 4B, steering
engine 400 may include a first panel section 402-1 and a second
panel section 404-1 for a first M.times.N WSS and may include a
third panel section 402-2 and a fourth panel section 404-2 for a
second M.times.N WSS. In this case, first panel section 402-1 and
third panel section 402-2 may include areas for receiving dispersed
spectrum beams associated with common port beam steering. In
contrast, second panel section 404-1 and fourth panel section 404-2
may include areas for receiving concentrated, non-dispersed
spectrum beams associated with add/drop port beam steering. As
shown, different geometric configurations of panel sections within
steering engines 400/400' may be possible.
In some implementations, first panel section 402-1 and third panel
section 402-2 may be considered a single panel section and second
panel section 404-1 and fourth panel section 404-4 may be
considered another single panel section. In some implementations,
other arrangements of panel sections may be possible, such as other
quantities of panel sections, other layouts of panel sections,
and/or the like. In this way, steering engine 400 enables
deployment of a twin M.times.N WSS (e.g., twin 4.times.16 WSSs), a
triple M.times.N WSS, a quad M.times.N WSS, and/or the like with a
reduced form factor, reduced cost, and improved durability relative
to deploying 2 or even 4 MEMS micromirror arrays to perform beam
steering for the twin M.times.N WSS.
In some implementations, each common port beam (e.g., each 3 common
port respectively associated with first panel section 402-1 and
third panel section 402-2) may be steerable from associated common
ports to any add/drop port (e.g., via the set of 10 areas of each
respectively associated with second panel section 404-1 and fourth
panel section 404-4). In some implementations, the common port
beams and the add/drop port beams may be associated with a maximum
steering angle relating to a quantity of areas for beam
steering.
As indicated above, FIG. 4 is provided merely as an example. Other
examples may differ from what is described with regard to FIG.
4.
FIG. 5 is a diagram of an example implementation 500 of a beam
steering engine 502, which includes panel sections 504 and 506, and
optical element 508 aligned to beam steering engine 502. As shown
in FIG. 5, beam steering engine 502 may include first and second
panel sections 504-1 and 504-2 for first beam steering of first
beams 510-1 and 510-2 (e.g., common port beam steering for
corresponding WSSs of a twin M.times.N WSS) and third and fourth
panel sections 506-1 and 506-2 for second beam steering of second
beams 512-1 and 512-2 (e.g., add/drop port beam steering for the
corresponding WSSs). In this case, optical element 508 is aligned
to third and fourth panel sections 506-1 and 506-2 to divert beams
512-1 and 512-2 to a different direction than beams 510-1 and
510-2. Although first and second panel sections 504-1 and 504-2 and
third and fourth panel sections 506-1 and 506-2 are shown as
conceptually separate sections that are side-by-side, other
configurations are possible, such as configurations where areas for
beam steering for non-dispersed beams are interspersed with areas
for beam steering for dispersed beams.
In this way, optical element 506 enables use of beam steering
engine 502 for multiple functionalities (e.g., the first beam
steering and the second beam steering) by ensuring that beams 510
are directed to different optical components within the twin
M.times.N WSS than beams 512. In some implementations, optical
element 506 may be a prism, a mirror (e.g., a fold mirror, and/or
the like). In some implementations, rather than optical element 506
being aligned to third and fourth panel sections 506-1 and 506-2 to
divert beams 512, optical element 506 may be aligned to first and
second panel sections 504-1 and 504-2 to divert beams 510. In
another example, rather than using an optical element 508, such as
a prism, beam steering engine 502 may be aligned to, for example, a
liquid crystal polarization rotator cell and a birefringent
prism.
As indicated above, FIG. 5 is provided merely as an example. Other
examples may differ from what is described with regard to FIG.
5.
FIG. 6 is a flowchart of an example process 600 for configuring a
beam steering engine to perform add/drop port beam steering and
common port beam steering in a WSS. In some implementations, one or
more process blocks of FIG. 6 may be performed by a control device,
such as a control device of a WSS, a control device of an optical
communications system, a control device external to the optical
communications system, and/or the like.
As shown in FIG. 6, process 600 may include determining a
configuration for a LCOS panel (block 610). For example, the
control device (e.g., using one or more processors, one or more
memories, and/or the like) may determine the configuration for the
LCOS panel, as described above. For example, the control device may
identify a set of panel sections to assign for a set of beam
steering functionalities. In this case, the control device may
identify a first panel section for a dispersed beam steering
functionality (e.g., common port beam steering) a second panel
section for a non-dispersed beam steering functionality (e.g.,
add/drop port beam steering), and/or the like. In some
implementations, the control device may identify an arrangement for
the set of panel sections. For example, the control device may
determine where to define the set of panel sections based on an
arrangement of optical components in a WSS that includes the LCOS.
In some implementations, the control device may identify panel
sections for multiple WSSs. For example, in a twin WSS
configuration, the control device may identify panel sections for
beam steering for a first WSS and panel sections for beam steering
for a second WSS. Additionally, or alternatively, the control
device may identify panel sections for higher density WSS
configurations, such as routing devices with greater than two WSSs
in a single optical node.
As further shown in FIG. 6, process 600 may include configuring a
first panel section of the LCOS panel (block 620). For example, the
control device (e.g., using one or more processors, one or more
memories, and/or the like) may configure the first panel section of
the LCOS panel, as described above. In some implementations, the
control device may transmit a control signal to the LCOS panel to
configure the first panel section. For example, the control device
may instruct the LCOS panel to assign a subset of pixels to a
particular configuration to perform a particular beam steering
functionality, thereby defining the first panel section. In some
implementations, the control device may instruct the LCOS panel to
assign the subset of pixels to multiple configurations. For
example, the control device may configure a first group of pixels
to perform beam steering for a first beam (e.g., a wavelength
channel sub-beam), a second group of pixels to perform beam
steering for a second beam, a third group of pixels to perform beam
steering for a third beam, and/or the like. In this way, the LCOS
panel enables beam steering for an M.times.N WSS, a twin M.times.N
WSS, a higher density (e.g., three or more) M.times.N WSS, and/or
the like.
As further shown in FIG. 6, process 600 may include configuring a
second panel section of the LCOS panel (block 630). For example,
the control device (e.g., using one or more processors, one or more
memories, and/or the like) may configure the second panel section
of the LCOS panel, as described above. In some implementations, the
control device may transmit a control signal to the LCOS panel to
configure the second panel section. For example, the control device
may instruct the LCOS panel to assign a subset of pixels to a
particular configuration to perform a particular beam steering
functionality, thereby defining the first panel section. In some
implementations, the control device may configure the first panel
section and the second panel section (and/or any other panel
sections) using a single control signal. In some implementations,
the control device may configure the first panel section using a
first control signal and the second panel section using a second
control signal.
Process 600 may include additional implementations, such as any
single implementation or any combination of implementations
described herein and/or in connection with one or more other
processes described elsewhere herein.
Although FIG. 6 shows example blocks of process 600, in some
implementations, process 600 may include additional blocks, fewer
blocks, different blocks, or differently arranged blocks than those
depicted in FIG. 6. Additionally, or alternatively, two or more of
the blocks of process 600 may be performed in parallel.
The foregoing disclosure provides illustration and description, but
is not intended to be exhaustive or to limit the implementations to
the precise forms disclosed. Modifications and variations may be
made in light of the above disclosure or may be acquired from
practice of the implementations.
As used herein, the term "component" is intended to be broadly
construed as hardware, firmware, and/or a combination of hardware
and software.
Some implementations are described herein in connection with
thresholds. As used herein, satisfying a threshold may, depending
on the context, refer to a value being greater than the threshold,
more than the threshold, higher than the threshold, greater than or
equal to the threshold, less than the threshold, fewer than the
threshold, lower than the threshold, less than or equal to the
threshold, equal to the threshold, or the like.
It will be apparent that systems and/or methods described herein
may be implemented in different forms of hardware, firmware, or a
combination of hardware and software. The actual specialized
control hardware or software code used to implement these systems
and/or methods is not limiting of the implementations. Thus, the
operation and behavior of the systems and/or methods are described
herein without reference to specific software code--it being
understood that software and hardware can be designed to implement
the systems and/or methods based on the description herein.
Even though particular combinations of features are recited in the
claims and/or disclosed in the specification, these combinations
are not intended to limit the disclosure of various
implementations. In fact, many of these features may be combined in
ways not specifically recited in the claims and/or disclosed in the
specification. Although each dependent claim listed below may
directly depend on only one claim, the disclosure of various
implementations includes each dependent claim in combination with
every other claim in the claim set.
No element, act, or instruction used herein should be construed as
critical or essential unless explicitly described as such. Also, as
used herein, the articles "a" and "an" are intended to include one
or more items, and may be used interchangeably with "one or more."
Further, as used herein, the article "the" is intended to include
one or more items referenced in connection with the article "the"
and may be used interchangeably with "the one or more."
Furthermore, as used herein, the term "set" is intended to include
one or more items (e.g., related items, unrelated items, a
combination of related and unrelated items, etc.), and may be used
interchangeably with "one or more." Where only one item is
intended, the phrase "only one" or similar language is used. Also,
as used herein, the terms "has," "have," "having," or the like are
intended to be open-ended terms. Further, the phrase "based on" is
intended to mean "based, at least in part, on" unless explicitly
stated otherwise. Also, as used herein, the term "or" is intended
to be inclusive when used in a series and may be used
interchangeably with "and/or," unless explicitly stated otherwise
(e.g., if used in combination with "either" or "only one of").
* * * * *